In an existing biometrics authentication device, when biological information extracted from a photographed image and registered biological information match each other, identity is determined. The biological information includes features that denote palm prints, veins, and the like, and when biometrics authentication is performed by using the feature denoting a vein, the feature denoting a palm print needs to be separated from the photographed image such that as much as possible only the feature denoting a vein is included in the biological information. As an example of a method for separating the feature denoting a palm print, a method for optically separating the feature denoting a palm print by using a polarizing filter is known. As another example of the method, a method using plural-wavelength photographing is known.
Related Art Document: A. Ross, A. K. Jain, and J. Reisman, “A Hybrid fingerprint matcher”, Pattern Recognition, vol. 36, no. 7, pp. 1661-1673, 2003.